There are several design options available to make high data rate writers. One of the major requirements for higher frequency extendability is to reduce yoke length and inductance in order to have fast saturation. Given fast saturation during the writing process, one can have better overwrite and cold overwrite performance at higher frequency. Some designs for faster write heads have the planar writer with a short yoke length. However, one of the drawbacks of this design is the coil real estate utilization which creates either high DC coil resistance or requires a small number of coil turns.
In FIG. 1 we show a typical write head of the prior art. Seen there is magnetic shield 11 which is separated from the lower magnetic pole by insulating layer 12. The lower pole is made up of two parts—base 13 and upper portion 14 which is open so that it forms a cavity. In this cavity is housed magnetic coil 16 which is seated on shallow pedestal 15. Insulating layers 17 and 18 cover the coil while insulating layer 19 serves to control throat height (see later). Non-magnetic gap layer 20 separates the lower coil structure from upper pole 21.
A routine search of the prior art was performed with the following references of interest being found:
In U.S. Pat. No. 6,325,947 B1, Garfunkel et al. show a process for a head with a short yoke while Nakajima et al. show a process for a head in U.S. Pat. No. 6,317,280 B1. Santini shows a process for a head in U.S. Pat. No. 6,339,523 B1 and related patents are U.S. Pat. No. 6,333,830 B2 (Rose et al.) and U.S. Pat. No. 6,304,414 B1 (Crue, Jr. et al.).